DIY gas generator repair

In detail: do-it-yourself gas generator repair from a real master for the site my.housecope.com.

A portable electric generator is an irreplaceable source of energy in conditions when there is no possibility of connecting to electric mains or the supply of electricity through them is interrupted. They use ordinary motor gasoline as fuel.

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A portable power generator will be useful wherever there is no permanent power source, for example, on a trip to nature.

Diesel power generators have a large mass, therefore, they are installed permanently as a backup source of electricity. Their gasoline counterpart is much lighter, therefore, it is quite mobile and is often taken with them to remote, inaccessible places. Therefore, in the event of a breakdown of a gas generator, it is extremely problematic to call a repair specialist; it becomes necessary to repair it yourself, with your own hands.

The device of a portable gasoline electric generator.

Such a machine is a mechanism for generating alternating current based on the synchronous rotation of its elements. Moreover, such a current, depending on its model and power, can be either single-phase or three-phase. The first has the ability to generate a voltage of 220 V and supply a single-phase load with current, which is necessary for electric lighting and the operation of most household electrical appliances. The second one can give a load in three phases and provide a voltage of 380 V, which makes it possible to connect, first of all, welding machines.

The gas generator consists of an electric generator and a gasoline engine that supplies it with energy. They are connected to each other by a special elastic coupling. A metal box is installed near the generator, where a device for turning it on, instruments for measuring operating parameters and automatic fuses in case of short circuits are mounted. The gasoline engine can have from 1 to 8 cylinders, depending on the required power, and also be two- or four-stroke. The latter are used more often, since they are more economical and have a higher efficiency. The method of switching on can be either from a spark obtained mechanically with the help of a manual drive, or from a battery.

Video (click to play).

The main reasons for failures in the operation of a portable gas generator can be either engine breakdown or failure of an electric generator. To find out the specific cause of the malfunction, you will have to check one by one all the nodes that can cause the failure.

Generator internal circuit diagram: 1. Fuel filters. 2. Crankshaft. 3. Air filter. 4. Part of the ignition system. 5. Cylinder. 6. Valve. 7. Crankshaft bearing.

In addition, the load on the generator may exceed its capacity. Then you need to turn it off and check the work. If, during the operation of the unit, smoke begins to rise from it and a burning smell appears, it means that a short circuit has occurred in the winding, then self-repair is extremely problematic, a complete rewinding of the windings is needed.

In general, repairing a gas generator on your own is quite affordable even in the field.

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Gasoline generators, even if they are made in China, very reliable with proper care... Nevertheless, during their operation, small problems can arise that can usually be quickly fixed with your own hands. Serious breakdowns with the knowledge of the owner of the device and the principle of operation of the generator will also not be able to disable it for a long time.

If you arrange possible malfunctions of the gas generator in a kind of rating, you get the following list:

  • Failure or contamination of the spark plug: difficult or impossible starting, unstable operation.
  • Clogged carburetor: difficult starting, excessive fuel consumption, unstable operation under constant load.
  • Failure of the ignition coil: no spark, inability to start.
  • Starter breakdowns: breakage, biting of the cable, destruction of the ratchet.
  • Violation of valve clearances: difficult starting, increased noise during operation.
  • Wear of brushes (on synchronous generators) - lack of output voltage.
  • Speed ​​governor malfunction: floating engine speed, dips when changing the load.
  • Wear of the bearings of the crankshaft and the rotor of the generator - an increase in operating noise, oil leakage.
  • Wear of the cylinder, piston rings - difficult starting of a cold engine, excessive oil consumption.

It does not take into account breakdowns that result from a gross violation of the rules for operating the generator: for example, seizures on the crankshaft neck due to insufficient oil level, burnout of the generator windings or voltage converter (on inverter gas generators) with frequent overloads.

In fact, malfunctions of a gasoline generator can be divided into three groups: mechanical, electrical and fuel / ignition system malfunctions.

Difficulty starting the generator, which manifested itself suddenly and not accompanied by an increase in engine noise, is a clear sign of either deviations in the operation of the carburetor (too lean or rich mixture), or a faulty ignition system (weak or intermittent spark formation). Since the diagnostics of the state of these systems is interconnected, it is combined into one section.

Remove the spark plug and inspect the carbon deposits on the electrodes.

  • Dense and dry black carbon deposits - a sign of a rich mixture (the carburetor is faulty, the air filter is clogged);
  • Oily black carbon - a sign of severe wear of the piston rings, oil enters the combustion chamber;
  • White soot - a sign of running on a lean mixture, it is necessary to check the carburetor.
  • Brick brown carbon deposits - normal for carburetor engines.
  • Red, green-red carbon deposits - a consequence of working on low-quality fuel.

It is simple to check the performance of the ignition system itself because of its extreme simplicity: turn on the ignition, insert a known good spark plug into the plug cap and, putting it on the nearest metal part of the engine with its skirt, turn the recoil starter abruptly. If there is no spark, disconnect the ignition switch and the oil level sensor from the ignition coil in turn: if, when both elements are disconnected, there is still no spark, replace the ignition coil.

If the spark is present and strong enough (white or blue-white), remove the spark plug after several starting attempts. A candle filled with gasoline is a sign of an over-enrichment of the mixture, a dry one is a lack of fuel.

Sometimes, after long storage, the needle and the carburetor float stick and prevent gasoline from flowing inside. Several times sharply, but do not hit the float chamber lid very hard and start again.

The most common carburetor malfunction is contamination. The ingress of dirt into the air channels leads to an over-enrichment of the mixture, into the fuel jets - to a depletion. Dirt on the float shut-off needle leads to loss of tightness and overfilling of the float chamber, which will be immediately noticeable by the leakage of fuel from the carburetor.

Let's take a look at the carburetor maintenance on the example of a Honda GX engine - its design is typical for a gasoline generator.

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  • Remove the float chamber cover (4). Wash it in gasoline or a carburetor spray cleaner - dirt and deposits accumulate on the bottom.
  • Proceed in the same way with the gas valve sump (22).
  • Check if the gas valve is blown in the "open" position.
  • Take out the float shaft (3), take out the float and the shut-off needle (2). Blow out the channel with air.
  • Blow out the fuel jet (25), emulsion tube (11) and all carburetor passages with an aerosol cleaner or compressed air.
  • Remove the adjusting screw (5), blow out its channel. Then screw it in until it stops and loosen, depending on the type of air filter, by 2 (foam, paper filters) - 2.5 turns (cyclone filters).
  • Assemble the carburetor.

The electrical system of gas generators is quite reliable. Most often, you can face two problems: lack of battery charging on generators with electric start or lack of voltage at the generator output.

  • The lack of battery charging is a consequence of the failure of the rectifier or low-voltage winding. It is easy to check this system with your own hands: connect a 12-volt light bulb in parallel with the low-voltage winding of the generator and start it. A lit light means that the generator itself is working properly, and it is necessary to replace the rectifier.
  • The absence of voltage at the generator output is most often the result of wear on the brushes. Remove them and assess the degree of wear, replace if necessary. If your generator is an inverter type, check if the voltage comes to the input of the converter by connecting a low-power 220 V lamp in parallel with it.

Video about the phased repair of the gas generator